Breast density analysis for whole breast ultrasound images : Whole breast ultrasound density analysis

Chen, Jeon-Hor,Huang, Chiun-Sheng,Chien, Kuang-Che Chang,Takada, Etsuo,Moon, Woo Kyung,Wu, Jeffery H. K.,Cho, Nariya,Wang, Yi-Fa,Chang, Ruey-Feng Wiley (John WileySons) 2009 Medical physics Vol.36 No.11

<P>Breast density has been established as an independent risk factor associated with the development of breast cancer. The terms mammographic density and breast density are often used interchangeably, since most breast density studies are performed with projection mammography. It is known that increase in mammographic density is associated with an increased cancer risk. A sensitive method that allows for the measurement of small changes in breast density may provide useful information for risk management. Despite the efforts to develop quantitative breast density measurements from projection mammograms, the measurements show large variability as a result of projection imaging, differing body position, differing levels of compression, and variation of the x-ray beam characteristics. This study used two separate computer-aided methods, threshold-based and proportion-based evaluations, to analyze breast density on whole breast ultrasound (US) imaging and to compare with the grading results of three radiologists using projection mammography. Thirty-two female subjects with 252 images per case were included in this study. Whole breast US images were obtained from an Aloka SSD-5500 ultrasound machine with an ASU-1004 transducer (Aloka, Japan). Before analyzing breast density, an adaptive speckle reduction filter was used for removing speckle noise, and a robust thresholding algorithm was used to divide breast tissue into fatty or fibroglandular classifications. Then, the proposed approaches were applied for analysis. In the threshold-based method, a statistical model was employed to determine whether each pixel in the breast region belonged to fibroglandular or fatty tissue. The proportion-based method was based on three-dimensional information to calculate the volumetric proportion of fibroglandular tissue to the total breast tissue. The experimental cases were graded by the proposed analysis methods and compared with the ground standard density classification assigned by a majority voting of three experienced breast radiologists. For the threshold-based method, 28 of 32 US test cases and for the proportion-based density classifier, 27 of 32 US test cases were found to be in agreement with the radiologist 'ground standard' mammographic interpretations, resulting in overall accuracies of 87.5% and 84.4%, respectively. Moreover, the concordance values of the proposed methods were between 0.0938 and 0.1563, which were less than the average interobserver concordance of 0.3958. The experiment result showed that the proposed methods could be a reference opinion and offer concordant and reliable quantification of breast density for the radiologist.</P>

Catheter Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

Fa-Po Chung,Chin-Yu Lin,Yenn-Jiang Lin,Shih-Lin Chang,Li-Wei Lo,Yu-Feng Hu,Ta-Chuan Tuan,Tze-Fan Chao,Jo-Nan Liao,Ting-Yung Chang,Shih-Ann Chen 대한심장학회 2018 Korean Circulation Journal Vol.48 No.10

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is predominantly an inherited cardiomyopathy with typical histopathological characteristics of fibro-fatty infiltration mainly involving the right ventricular (RV) inflow tract, RV outflow tract, and RV apex in the majority of patients. The above pathologic evolution frequently brings patients with ARVD/C to medical attention owing to the manifestation of syncope, sudden cardiac death (SCD), ventricular arrhythmogenesis, or heart failure. To prevent future or recurrent SCD, an implantable cardiac defibrillator (ICD) is highly desirable in patients with ARVD/C who had experienced unexplained syncope, hemodynamically intolerable ventricular tachycardia (VT), ventricular fibrillation, and/or aborted SCD. Notably, the management of frequent ventricular tachyarrhythmias in ARVD/C is challenging, and the use of antiarrhythmic drugs could be unsatisfactory or limited by the unfavorable side effects. Therefore, radiofrequency catheter ablation (RFCA) has been implemented to treat the drug-refractory VT in ARVD/C for decades. However, the initial understanding of the link between fibro-fatty pathogenesis and ventricular arrhythmogenesis in ARVD/C is scarce, the efficacy and prognosis of endocardial RFCA alone were limited and disappointing. The electrophysiologists had broken through this frontier after better illustration of epicardial substrates and broadly application of epicardial approaches in ARVD/C. In recent works of literature, the application of epicardial ablation also successfully results in higher procedural success and decreases VT recurrences in patients with ARVD/C who are refractory to the endocardial approach during long-term follow-up. In this article, we review the important evolution on the delineation of arrhythmogenic substrates, ablation strategies, and ablation outcome of VT in patients with ARVD/C.

Ammonium Acetate Supplement Strategy for Enhancement of Chaetominine Production in Liquid Culture of Marine-Derived Aspergillus fumigatus CY018

( Chang-qing Liu ),( Xing-chen Wei ),( Fa-liang An ),( Yan-hua Lu ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.4

Pharmacological research on (CHA), a marine-derived quinazolinone alkaloid with significant cytotoxic activity, is restricted by low yields and is a problem that needs to be settled urgently. In this work, the selection of additional nitrogen sources and the optimization of additional concentrations and longer fermentation times using ammonium acetate, were investigated. CHA production was optimized to 62.1 mg/l with the addition of 50 mM ammonium acetate at 120 h of the fermentation in the shaker flask. This feeding strategy significantly increased 3- deoxy-arabino-heptulosonate-7-phosphate synthase activity and transcript levels of critical genes (laeA, dahp, and trpC) in the shikimate pathway compared with the non-treatment group. In addition, the selection of the feeding rate (0.01 and 0.03 g/l·h) was investigated in a 5-L bioreactor. As a result, CHA production was increased by 57.9 mg/l with a 0.01 g/l·h ammonium acetate feeding rate. This work shows that the strategy of ammonium acetate supplementation had an effective role in improving CHA production by Aspergillus fumigatus CY018. It also shows that this strategy could serve as an important example of large-scale fermentation of a marine fungus in submerged culture.

WEIGHTED EVIDENTIAL FUSION METHOD FOR FAULT DIAGNOSIS OF MECHANICAL TRANSMISSION BASED ON OIL ANALYSIS DATA

Yan Shu-fa,Ma Biao,Zheng Chang-song,Chen Man 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.5

Condition monitoring (CM) and fault diagnosis are critical for the stable and reliable operation of mechanical transmissions. Mechanical transmission wear, which leads to changes in the physicochemical properties of the lubrication oil and thus severe wear, is a slow degradation process that can be monitored by oil analysis, but the actual degradation degree is difficult to evaluate. To solve this problem, we propose a new weighted evidential data fusion method to better characterize the degradation degree of the mechanical transmission through the fusion of multiple CM datasets from oil analysis. This method includes weight allocation and data fusion steps that lead to a more accurate data-based fault diagnostic result for CM. First, the weight of each evidence is modeled with a weighted average function by measuring the relative scale of the permutation entropy from each CM dataset. Then, the multiple CM datasets are fused by the Dempster combination rule. Compared with other evidential data fusion methods, the proposed method using the new weight allocation function seems more reasonable. The rationality and superiority of the proposed method were evaluated through a case study involving an oilbased CM dataset from a power-shift steering transmission.

Fermentation Optimization and Industrialization of Recombinant Saccharopolyspora erythraea Strains for Improved Erythromycin A Production

Xiang Zou,Chang-fa Chen,Xia-chang Qi,Jiang-chao Qian,Ju Chu,Ying-ping Zhuang,Si-liang Zhang,Wei Zeng,Wan-jun Li 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.6

Improvement of Erythromycin A (Er-A) production and purity by metabolic engineering of the industrial erythromycin-producing strains Saccharopolyspora erythraea strians ZL1004 and ZL1007, in which the amounts of tailoring enzymes EryK (a P450 hydroxylase)and EryG (an S-adenosylmethionine-dependent O-methyltransferase)for biotransformation of Erythromycin D to Er-A were modulated, was performed in a 50 L fermentor. Addition of 15 g/L of corn steep liquor to the medium increased Er-A production; maximum Er-A production was 8,196 U/mL at 191 h, which was 81.8% higher than that of control (4,507 U/mL at 184 h). Er-B impurities were completely eliminated, whereas Er-C impurities were only 153 U/mL at 191 h. Analysis of intra- and extracellular metabolites and key enzyme activities in central carbon metabolism revealed that the pool of TCA cycle intermediates was enhanced by the addition of corn steep liquor and induced an increase in erythromycin biosynthesis. There were no significant differences between strains ZL1004 and ZL1007 regarding Er-A production and impurity accumulation. Compared to wild type strain,Er-A production was improved by 23.9% while Er-C was reduced by 83.9% and Er-B was completely eliminated. Furthermore, fermentation of recombinant strain ZL1004was successfully scaled up from laboratory scale (50 L fermentor) to industrial scale (25 and 132 m3), with similar levels of Er-A production and purity obtained.

Diversity of Arbuscular Mycorrhizal Fungi Associated with a Sb Accumulator Plant, Ramie (Boehmeria nivea), in an Active Sb Mining

( Yuan Wei ),( Zhi Peng Chen ),( Feng Chang Wu ),( Ji Ning Li ),( Yu Xian Shangguan ),( Fa Sheng Li ),( Qing Ru Zeng ),( Hong Hou ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.8

Arbuscular mycorrhizal fungi (AMF) have great potential for assisting heavy metal hyperaccumulators in the remediation of contaminated soils. However, little information is available about the symbiosis of AMF associated with an antimony (Sb) accumulator plant under natural conditions. Therefore, the objective of this study was to investigate the colonization and molecular diversity of AMF associated with the Sb accumulator ramie (Boehmeria nivea) growing in Sb-contaminated soils. Four Sb mine spoils and one adjacent reference area were selected from Xikuangshan in southern China. PCR-DGGE was used to analyze the AMF community composition in ramie roots. Morphological identification was also used to analyze the species in the rhizosphere soil of ramie. Results obtained showed that mycorrhizal symbiosis was established successfully even in the most heavily polluted sites. From the unpolluted site Ref to the highest polluted site T4, the spore numbers and AMF diversity increased at first and then decreased. Colonization increased consistently with the increasing Sb concentrations in the soil. A total of 14 species were identified by morphological analysis. From the total number of species, 4 (29%) belonged to Glomus, 2 (14%) belonged to Acaulospora, 2 (14%) belonged to Funneliformis, 1 (7%) belonged to Claroideoglomus, 1 (7%) belonged to Gigaspora, 1 (7%) belonged to Paraglomus, 1 (7%) belonging to Rhizophagus, 1 (7%) belonging to Sclervocystis, and 1 (7%) belonged to Scutellospora. Some AMF sequences were present even in the most polluted site. Morphological identification and phylogenetic analysis both revealed that most species were affiliated with Glomus, suggesting that Glomus was the dominant genus in this AMF community. This study demonstrated that ramie associated with AMF may have great potential for remediation of Sb-contaminated soils.

Catheter Ablation of Peri-Conduit Ventricular Tachycardia in a Patient with Rastelli Procedure for Double Outlet Right Ventricle with Malposition of Great Arteries

Abigail Louise D. Te,Fa-Po Chung,Chin-Yu Lin,Atul Prabhu,Pi-Chang Lee,Shih-Ann Chen 대한심장학회 2017 Korean Circulation Journal Vol.47 No.4

Multiscale Belief Propagation on Concrete CT Image Fast Segmentation

Zhao Liang,Lu Jun,Chen Deng-feng,Li chang-hua,Dang Fa-ning 보안공학연구지원센터(IJGDC) 2013 International Journal of Grid and Distributed Comp Vol.6 No.6

The accuracy and clinical applicability of a sensor based electromagnetic nonfluoroscopic catheter tracking system

Shinya Yamada,Li-Wei Lo,Yenn-Jiang Lin,Shih-Lin Chang,Fa-Po Chung,Yu-Feng Hu,Ta-Chuan Tuan,Tze-Fan Chao,Jo-Nan Liao,Chin-Yu Lin,Shih-Ann Chen 대한심장학회 2019 Korean Circulation Journal Vol.49 No.1

Background and Objectives: The differences between electromagnetic-based mapping (EM) and impedance-based mapping (IM) in 3D anatomical reconstruction have not been fully clarified. We aimed to investigate the anatomical accuracy between EM (MediGuide™) and IM (EnSite Velocity™) systems. Methods: We investigated 15 consecutive patients (10 males, mean age 58±9 years) who underwent pulmonary veins (PVs) isolation for paroxysmal atrial fibrillation (PAF). Contrast-enhanced computed tomography (CT) image of the left atrium (LA) was acquired before ablation and the 3D geometry of the LA was constructed using EM during ablation procedure. We measured the 4 PV angles between the main trunk of each PV and the posterior LA after field scaling. Additionally, the posterior LA surface area was measured. The variables were compared to those of CT-based geometry. A control group of 40 patients who underwent conventional PVs isolation using IM were also evaluated. Results: The actual and relative changes of EM and CT-based geometry in all PV angles and posterior LA were significantly smaller compared to those of IM and CT-based geometry. Intraclass correlation coefficient (ICC) between EM and CT-based geometry were 0.871 (right superior pulmonary vein [RSPV]), 0.887 (right inferior pulmonary vein [RIPV]), 0.853 (left superior pulmonary vein [LSPV]), 0.911 (left inferior pulmonary vein [LIPV]), and 0.833 (posterior LA). On the other hand, ICC between IM and CT-based geometry were 0.548 (RSPV), 0.639 (RIPV), 0.691 (LSPV), 0.706 (LIPV), and 0.568 (posterior LA). Conclusions: Image integration with EM enables high accurate visualization of cardiac anatomy compared to IM in PAF ablation.

Equal Z standard-setting method to estimate the minimum number of panelists for a medical school’s objective structured clinical examination in Taiwan: a simulation study

Ying-Ying Yang,Pin-Hsiang Huang,Ling-Yu Yang,Chia-Chang Huang,Chih-Wei Liu,Shiau-Shian Huang,Chen-Huan Chen,Fa-Yauh Lee,Shou-Yen Kao,Boaz Shulruf 한국보건의료인국가시험원 2022 보건의료교육평가 Vol.19 No.-

Purpose Undertaking a standard-setting exercise is a common method for setting pass/fail cut scores for high-stakes examinations. The recently introduced equal Z standard-setting method (EZ method) has been found to be a valid and effective alternative for the commonly used Angoff and Hofstee methods and their variants. The current study aims to estimate the minimum number of panelists required for obtaining acceptable and reliable cut scores using the EZ method. Methods The primary data were extracted from 31 panelists who used the EZ method for setting cut scores for a 12-station of medical school’s final objective structured clinical examination (OSCE) in Taiwan. For this study, a new data set composed of 1,000 random samples of different panel sizes, ranging from 5 to 25 panelists, was established and analyzed. Analysis of variance was performed to measure the differences in the cut scores set by the sampled groups, across all sizes within each station. Results On average, a panel of 10 experts or more yielded cut scores with confidence more than or equal to 90% and 15 experts yielded cut scores with confidence more than or equal to 95%. No significant differences in cut scores associated with panel size were identified for panels of 5 or more experts. Conclusion The EZ method was found to be valid and feasible. Less than an hour was required for 12 panelists to assess 12 OSCE stations. Calculating the cut scores required only basic statistical skills.